Elongated channel draw bench for sheet shaping machine operating on the forming-by-drawing principle and having lubricating means for a carriage slidable in said draw bench



F. ANDERSON Feb. 2, 1960 E m HD 0N AHA E GLE NFC I IA PCT ANR um PC T 1.AE %w B WWW AF RR R 080 F N mm '1 m MA N S ENG BTNN mfl WOAE RFCL D IBER HBD ETUT N L... n vG m m I @TH TA AR CE P W0 m.

11 Sheets-Sheet 1 Original Filed Feb. 8, 1955 Feb 2, 1960 2,923,342CHINE AND F. ANDERSON RAW ELONGATED CHANNEL D BENCH FOR SHEET SHAPING MAOPERATING ON THE FORMING-BY-DRAWING PRINCIPLE HAVING LUBRICATING MEANSFOR A CARRIAGE SLIDABLE IN SAID DRAW BENCH 6b. 8, 1955 l]. Sheeta-5heet3 Original Filed F F. ANDERSON Feb. 2, 1960 I 2,923,342 BENCH FOR SHEETSHAPING MACHINE OPERATING ON THE FORMING-BY-DRAWING PRINCIPL AND FOR ACARRIAGE AW BENCH ELONGATED CHANNEL DRAW HAVING LUBRICATING MEANSSLIDABLE IN SAID DR Original Filed Feb. 8, 1955 11 Sheets-Sheet 4 W m MM M W m 1960 F. ANDERSON 2,923,342

ELONGATED CHANNEL DRAW BENCH FOR SHEET SHAPING MACHINE OPERATING on THEFORMING-BY-DRAWING PRINCIPLE AND HAVING LUBRICATING MEANS FOR A CARRIAGESLIDABLE m SAID DRAW BENCH Original Filed Fab. 8, 1955 A 11 Sheets-Sheet5 2 4 h a .K- lldll 5 4 b 4 4 5 w 3 2 3 h 3 96 mvflwwgw WT. Tm Z IIIJW 2H ,IIIL |1|I H111 \\v\ A .H.. r| 4+ 1 QT- M6 N1 5 I I N 4 px M a .724 aK. I. 1 9 & 0 9/ mu $90 6 a w w 4 4 6533 333666 6 lV l/ /N 1/5 7019FIFO/{MAN A/vofkjalv BY M A TTOR/VEY Feb. 2, 1960 F. ERSON 2,923,342

AND ELONGATED CHANNEL DRAW BENCH FOR SHEET SHAPING MACHINE OPERATING ONTHE FORMING-BY-DRAWING PRINCIPLE AND HAVING LUBRICATING MEANSFOR ACARRIAGE SLIDABLE IN SAID DRAW BENCH Original Filed Feb. 8, 1955 llSheets-Sheet 6 ma 9 /3 7g A77'0/P/VEY Feb. 2, 1960 F. ANDERSON 2,923,342

ELONGATED CHANNEL DRAW BENCH FOR SHEET SHAPING MACHINE OPERATING on THEFORMING-BY-DRAWING PRINCIPLE AND HAVING LUBRICATING MEANS FOR A CARRIAGESLIDABLE IN SAID DRAWBENCH Original Filed Feb. 8, 1955 11 Sheets-Sheet TFRO/ IVAN ANDERSON 92 99 89 93 m4 M4 95 00 036 v 89 T T I I l I E/-v/vroR I L :1

ATTORNEY Feb. 2, 1960 F. ANDERSON 2,923,342

ELONGATED CHANNEL DRAW BENCH FOR SHEET SHAPING MACHINE OPERATING ON THEFORMINGBY-DRAWING PRINCIPLE AND HAVING LUBRICATING MEANS FOR A CARRIAGE"SLIDABLE IN SAID DRAW BENCH Original Filed Feb. 8, 1955 ll Sheets-Sheet8 l I 1 I L I l l I l I s F- ANDERSON ENCH FOR SHEET SHAPING MING Feb.2, 1960 2,923,342 MACHINE E AND ELONGATED CHANNEL-.- 0

RAW B OPERATING ON THE FOR BY-DRAWING PRINCIPL HAVING LUBRICATING MEANSFOR A CARRIAGE SLIDABLE IN SAID DRAW BENCH Ongmal Flled Feb 8, 1955 llSheets-Sheet 9 3mm 5% 8mm IIIIII.+I+ II I I I N I II I W I I W III M I.Jl I IANI Ii .1 mg L N? L. I I I II I I IFI I I I V I I FH I I I I I I%I Q. MY Nm mvm M 6mm III tIII M IIIIII I 1. I I IUIMI I I H. V I I I I HI MI H I H I H I H I E F. ANDERSON RAW BENCH FOR SHEET Feb. 2, 19602,923,342 SHAPING MACHINE ELgggATED CHANNEL D RATING ON THEFORMING-BY-DRAWING PRINCIPLE AND nAvmc l gglz r ggw gc mmus FOR ACARRIAGE AI D Original Filed Feb. 8, 1955 D RAW BENCH 1'1 Sheets-Sheeti0 h H n n h. n c n n H w P 5 5 =W H H H :H N w NN wbmfi H. m m .CRHHM.13cm.wmwwww m w m H w ?c. n flm C g \E E Q .e H mc fluw H E A091. AIIIIY m mm mm Feb. 2, 1960 ANDERSO OPERATING ON THE MI WING PRINCIPLEAND HAVING LUBRI ING MEAN OR A C IAGE IN SAI SLIDABLE D DRAW BENCOriginal Filed Feb. 8, .1955 ll Sheets-Sheet 11 m5 ifi g ATTORNEY F. N2,923,342 ELONGATED CHANNEL DRAW BENCH FOR SHEET SHAPING MACHINE NG BY-United St Patent O ELONGATED CHANNEL DRAW BENCH FOR SHEET SHAPINGMACHINE OPERATING ON THE FORMING-BY-DRAWING PRINCIPLE AND HAVINGLUBRICATING MEANS FOR A CARRIAGE SLIDABLE IN SAID DRAW BENCH FrohmanAnderson, Las Vegas, Nev.

Original application February 8, 1955, Serial No. 436,77 3, now PatentNo. 2,851,080, dated September 9, 1958. Divided and this applicationNovember 1, 1957, Serial No. 693,932

7 Claims. (Cl. 15332) This application is a division of applicationSerial No. 486,773, filed February 8, 1955, now Patent No. 2,851,- 080,which relates to a machine for shaping metal sheets into compound curvesby pulling the sheets edgewise from one end to the other over a seriesof forming elements the Working faces of which differ in contourtransversely of the sheets and are disposed in stepped relation, arestraining or hold-back force being exerted on the sheets in oppositionto the pulling force to subject the sheets to stresses beyond theiryield point. This operation in the said parent application is termedforming-by-drawing.

Such machines are composed of three main functional componentscomprising the sheet forming structure, a draw bench including a poweractuated carriage for the mechanism that is to be translated in theperformance of the operation, and the sheet pulling mechanism attachedto and propelled by the carriage for gripping and pulling the sheetsthrough the forming structure.

This application relates to the draw bench construction. Morespecifically, it relates to the draw bench and its relation to theforming structure including the means for lubricating the draw benchslide or carriage.

One of the main functions of the carriage is to translate the jaws topull the sheets through the forming elements and, being thus heavilyloaded, it presents a problem of proper guidance and lubrication. Powermeans of considerable proportions are required and therefore suitabledisposition of the draw bench with respect to the forming structurepresents a problem.

In accordance with this invention, the work bench is supported upon thegear box or housing for the gearing, its ends being supported by legs.The gear box is supported upon the base to which are attached theuprights for the forming structure, being either directly in line withthe forming elements so that the jaws are carried over the bench, or atone side thereof in close proximity so that the jaws are carried by alaterally extending head,

The bench is U-shaped in cross section and serves as a guide for acarriage sliding therein. A rack on the bottom of the carriage isengaged by a bull gear in the gear box and is thus propelled. Because ofthe great stress to which the carriage is subjected by the up thrust ofthe feed gear and the pulling strain, the sides of the guide areprovided with an overhang which also requires lubrication.

In accordance with the invention, that bench is provided with a pair ofvertical oil ducts that communicate withan oil pressure source and leadto the under side of the carriage on opposite sides of the guide channeland through a branch to the underside of each overhang, therebyproviding lubrication for the top and bottom surfaces of the carriagenear each side edge, these surface portions bing preferably providedwith wear plates.

To distribute the oil on the under side of the bottom wear plates, alongitudinal groove is formed in the lower surface of each bottom wearplate which is continuous from end to end of the plates and is disposedin register with the respective vertical duct.

Also to lubricate the side edges of the carriage, these edges for adistance at each end are provided with wear plates and one or more rightangle passages in the slide provide communication from the respectivecontinuous longitudinal groove on the bottom face of the carriage to theside face where the face of the wear plate is recessed laterally foreffective oil retention and distribution. The longitudinal groove .isalso provided at intervals with a lateral recess for effectivedistribution of the oil on the under surface of the carriage.

Since thestress to which the carriage is subjected, due to the up thrustof the bull gear and the pulling stress, is concentrated on the portionof the draw bench onthe gear box' and at the delivery end, there is noneed for an overhang on the feed end of the bench, and, therefore, foreconomy, the overhang is discontinued from the gear box to the feed endof the bench; The oil duct in the overhang also feeds into alongitudinal groove on the top face of the top wear plate on each side,but since the portion of the groove outside the overhang is uncovered,it is obvious that the exposed portion cannot be connected to pressure.For this reason, the groove in each of the two top wear plates isinterrupted at points such that the uncovered portions of the grooves inthe retracted position of the carriage are not connected to the groovesections which are under pressure.

The length of the draw bench and carriage must,of course, be suited tothe length of the sheets to be drawn and in order that the carriage mayhave the capacity for operating on long sheets without the necessity forthe excessive travel when operating on short sheets, the'inventioncontemplates means to vary the length of the bench and carriage to adaptthem to the particular length of sheets being formed.

The invention has other objects and advantages as will appear from thefollowing description of the embodiment ofthe invention illustrated inthe accompanying drawings. 1

Fig. 1 is a side elevation of a machine embodying the invention,

Fig. 2 is a plan of the same.

Fig. 3 is a front elevation of the forming structure and a partialtransverse section of the draw bench on the line 33 of Fig. 1. t

Fig. 4 is a partial sectional view of the forming struc-' ture and of aportion of the draw bench structure on line 44 of Figs. 1 and 6.

Fig. 5 is a fragmentary detail on thesection line 5--5 of Fig. 4.

Fig. 6 is a vertical section of the machine on a plane central of theforming structure on line 6--6 of Figs. 3 and 4.

Fig. 7 is a plan of the gear box and enclosed mechanism on line 77 ofFigs. 1 and 8.

Fig. 8 is a vertical section on line 8-8 of Fig. 7.

Fig. 9 is a vertical section on line 99 of Fig. 7.

Fig. 10 is a partial elevation and partial section on line 1010 of Fig.8.

Fig. 11 is a fragmentary plan of a section of the draw bench withextension added, being generally as viewed on line 1111 of Fig. 12. r

Fig. 12 is a longitudinal section on broken section line 1212 of Fig.11.

Figs. 13 and 13a are fragmentary plans of the carriage varytheir-spacing in the direction of draw. means for this purpose areattached to the rearwardly slide and draw:bench,i:Fig. .13 being of the'forward end,

" of th'e draw bench and slide,-the section "being on line f 15-'--1'Sof Fig. 13.

Fig. 16is a fragmentary horizontal "section on line 16-16 of Fig. 15 andon a reduced scale.

"In :theillustrated construction; the-draw bench is disposed alongsidethe forming structure; 'all'being supported upon a common base. Theforming structure comprises three stages, which in the-embodiment shownare con' "gained between two uprights :attachedto the common 'ase.

"The" first stage of the forming structure. has.;a lower "'T-shapedfbodymember withthecross :headxextending between the uprights and-carryingjaforming and holdback element which presents a straight edge over whichthe sheer-is drawn and so determines 'the general path -of movement ofthe sheet. An-upper vertically sli'dable ranrmember opposes the crosshead and'cooperates' with the lower element to impose a regulatable'pressure upon the sheet, being --verticallyadjustable and guided 'withinthe uprights. The first stageis, therefore, known as the hold-backstage.

The second stage comprises -a ram 'member spanning -the:uprights--andguided therein for vertical adjustment, Afor'ming element carried by'theram member has a geometrical contour differing from that of thehold-back element of the first-stage and in operation is in steppedrelation to the first-stage element. It constitutes a drawover' formingelement.

The third 'stage also has a T-shaped body member with the cross headspanning the uprights. A forming element carried by the'cross head is ofa contour complernentary to that of the second stage element. That "is,if one is convex the-other is of a corresponding concaveshape. The thirdstage forming element is disposed beyond the' second stageelement in thedirection of draw and in stepped relation-thereto during operation sothat the sheet takes a reverse bend in its draw over the third stageelement, and engages-the third stage elementwith the side opposite thatwithwhich it engages the secondstage-element. 'The function of thisthird :stageis 'to compensate for the surface extension resulting fromthe draw over the second stage and-thus con- .trolthe coiling tendenciesof the sheet.

Means are provided to adjust the first and third-stages forward and backrelative'to thesecond stage so as to Power extending legs of theT-shaped members. Means are *alsoprovided totilt the first stage about acentral longitudinal'axis-and to raise and lower'the first stage as aunit about a transverse axis. These-relative movements 'oil the' firstand third stage elements have important functional efiects on thedrawing operation, as is fully explained in the said-parent application.

A base structure '10 hasat one'side a gear box 11 supported thereon, andlaterally of the gear box two spaced uprights 12and 13 are attached toand supported by the base. The gear box 11 abuts and is attached bykeys-to upright 13.

Thefirst stage structureis' shown in Figs. 4 and 6.

It has twosecondaryuprights*-14and-:i15 which contain both the lowerT-shaped member and-the upper ram fassembly so'that thesemay be'movedtogether-as a =unit relative'to the uprights 12 and-13, having guidingconnection therewith through rocker bearing plates 16 The upper firststage assembly comprises a top' fixed I bar 18 which spans the secondaryuprights and is adjustable in height between .gibs 19 .on the uprights,a ram 20 which is also a cross bar spanning the uprights and slideswithin gibs 21, and toggles 22 and 23 connected by bar 24. A hydrauliccylidner 25 has trunnions in bearing brackets 26 on ttop of fixed bar18, with its piston rod connected to the top end of a toggle operatinglever 27 that has its fulcrum pivot in bar 18 and is pivoted at itslower end to the pivot of bar 24. The lever 27 is double, the rear armbeing-slightly -wider1than the front as-indicated;in FigLZ'and by brokenlines in 'Fig. 4. The bar 18 is hollow, as shown.

It is desirable to adjust .the he'ight of the bar 18 for sheets ofdifferent thickness and, as shown in Figs. 4 and 5, the ends ofthebar 18are notchedand the gibs 19 are notched. Blocks.28 are inserted,in,thevrregistering notches and shims on top of .theblock. determinetheupward limit of movement ,of bar :18. :The adjustment of the bar 18 iseffected by screws 29 whichLscrew-through bridge pieces on ,top of the.gibs and into tapped holes in the bar.

A hold-back ielement 3 0.;has .a dove tail connection with. the bottomfaceofram 20. and,is clamped in place by clamp strip '31.,SmQQthingplatefiZis disposed immediately back of hold back element 30.

The lower first stage assembly Icomprises a T-shaped body member.33'havingla cross headf34 which spans thesecondary uprights I l-and I5and a rearwardly extending leg member 35. Ahold-back element 36 has adove tail connection with the top face of cross head 34 and is clampedin placeby'clamp strip 37; The hold-back element 36.1opposes the upperhold-back element 30 andis of complementary shape. The sheet S is fedbetween the two elements 30 'and'36 and between the smoothing plate 32and an opposing-smooting plate 38 on thelower first stage .body member33 immediately back of the. lower hold-back element'36.

Thefirst stage assemblyis dynamicallyxadjustable for- Wardly and'backward to alimited extent to and from the second stage. Thisisdonethrough a hydraulic cylinder 39, which, as shown in'Fig'Z,hasitsjpiston rod connected througha pivoted coupler 40 and links 4110 awrist pin 42 in the end of theleg member 35. The first stage structureis also dynarnicallytilted-about a longitudinal axis and. raised and,lowered about a transverse axis by hydraulic cylinders 43. For thispurpose, the T-shapedbody member33ofthe' lower first Stageas semblyissupported on thebase 'through a guide structure '44 which is "mountedfor; 1universalmovement througha gimbal mount "45. Thisguide structurehas two forwardlyextendingarms lla to which the pistons of cylinders43are-attached. *Th'e rearwardl-y extending leg '35 0f meniber33isguidedinthe guide-structure 44 in its dynamic adjustment -to and from tlresecond stage.

The second-stage assembly, asshown in Figs. 3 and 6,

has at the top "a fixed bar 46 spanning-and attached at its ends totheuprights 12 and' 13; *Supported by this bar through *toggles is a-twopart=ram which carries the second stage forming'element and is raisedand lowered by means of the toggles which are operatedbyahydraulic'cylinder' and piston; Thetwo parts'of the ram haveturn-buckle connection'providing for adjustment of the relativehorizontal disposition of the two parts of the ram.

The two parts-of the ram are upper bar 47 and lower elementcarrying bar48 which are connected-by--turnbuckles 49. Toggles 50 connect thefixedbar 46 and bar 47 of the ram, the toggle joints being connected by bar51. "The toggles are operated-by hydraulic cylinder 52" supported onbrackets 53 on-upright 13. The piston of the cylinder is connected tothe end of toggle-operating bar51 bypiston rod 54.

A counterweightSSfon the ram is loaded on the free endoflever 56 whichis-pivoted at its other end to the top edge of fixed bar 46 and has anextension beyond the t S ivot connected to the top edge of bar 47through links 57.

The ends of the ram bars 47 and 48 are constrained and guided by rails58 which are fastened on the uprights and enter into the slotted ends ofthe ram bars.

The lower edge portion of the ram bar 48 is thinner than the mainportion of the bar and a forming element 59 is fastened to its innerface, having a dovetail connection therewith and being secured in placeby a wedge member 60 hearing on its top edge and secured in place byscrews 60a. The forming element is a full length plate extending fromend to end of the ram and having a forming surface on its bottom edgewhich in the illustrated setting is downwardly curved. The work-engagingportion is a ridge at the entrance or inner side portion of the bottomedge, beyond or in front of which the bottom edge is raised and isopposed by the complementary shape work-engaging face of the third stageelement, as will be seen.

The T-shaped body member of the third stage has a carrier T-shapedstructure consisting of a cross head 61 and a rearwardly extending leg62, being supported and guided upon the super base structure 63. On thecross head 61 is the cross head 64 to the rear face of which the thirdstage forming element 65 is attached by a dovetail connection, andlocked in place by a wedge 66. This third stage forming element is afull length plate, the upper edge of which has a longitudinal concavecurvature substantially complementary of the second stage element,having as its work-engaging portion a raised ridge at its front or exitedge which opposes the raised portion of the second stage element beyondits work-engaging ridge portion.

The third stage body member, like the first stage member, is susceptibleof forward and back dynamic movement during the drawing operation. Forthis purpose, the rearwardly extending leg 62 has connection with ahydraulic cylinder 67 which is disposed in the super base structure asshown in Fig. 6. A cross head 68 is connected to the rear end of leg 62and to horizontally reciprocating piston rod 69 of cylinder 67, thecross head having depending legs 70 which have feet that are guidedunder cleats on base 10 (see Fig. 3).

The gearing in the gear box 11 is driven by the main power unit M1through the gear reduction in housing 71 and the coupling 72 (Fig. 2).The coupling engages and drives shaft 73 (Figs/7 and 8) which drivespinion 74. Shaft 73 is hollow and contains an internal pump shaftextension 75 which bears in the bearing 76 on an L-shaped base strip 77resting upon the top edges of two cross members 78 and 79, the otherbearing for shaft 73 being in the wall of the gear box. The member 79serves as across brace and extends diagonally, as shown, for clearancepurposes and has openings along-its bottom edge to provide freecommunication between the two sides of the member. The entire bottom ofthe gear box up to the member 78 constitutes an oil-collecting sump forreturned lubricating oil, as willbe described, 'and the member 78 servesto partition off a space 80 which is a tank for clean lubricating oil,filters 81 in the collecting sump delivering into the tank 80. The top8011 for the tank 80 has a removable cover 82.

The pump shaft 75 operates a pump 83 through an eccentric on the shaftand draws clean oil from the tank 80 through connection 84 and deliversit into a line 85 from which it is distributed to several points, aswill appear. v

The pinion 74 meshes with gear 86-the shaft of which bears in hearingsin the two sides of the gear box and has pinion 87 fixed thereon. Pinion87 meshes with bull gear88 the shaft of which bears in bearings in thesides of gear box 11. The hull gear meshes with and drives a rack on thecarriage as will now be described.

The top of the gear box is machined to form a seat for the fixed drawbench 89 which'guidesthe carriage,

6 the seating of the draw bench: upon the gear box being shown in Figs.9 and 10.

The draw bench is an elongated channel guide member which rests atsubstantially its mid-point on the gear box and has its extending endssupported at intervals by legs 90. The cross-sectional shape of the drawbench is shown in Figs. 9 and 10. The upstanding sides of the channelserve as side guides for the carriage and for a portion of its lengththe upper edges of the sides have inwardly' overhanging projections 89a.These overhangs extend from the left end of the draw bench as viewed inFig. 1 to somewhat beyond the middle of the gear box, as shown in Figs.2 and 13, and serve to oppose the upward thrust of the bull bear on thecarriage. They also have a function in the lubrication of the carriage,as will appear.

The bottom of the draw bench is provided with a longitudinal depressionor channel as appears in the cross-sectional views, for accommodation ofthe rack on the bottom of the carriage, and immediately over the bullgear the bottom of the bench is apertured to provide for the meshing ofthe bull gear with the rack, as shown in Fig. 8. Also a removable cover91 affords access to the interior of the gear box.

The carriage is a longitudinal sliding member 92 of a width fittingbetween the upright sides of the draw bench and, as will be seen, itcarries the draw mechanism as well as other parts which requiretranslation in the functioning of the machine. On its underside for theportion of its length corresponding to the length of its travel, thecarriage has a rack 93 secured thereto which occupies the longitudinalchannel or recess in the bottom of the draw bench. This rack is engagedby the bull gear.

The draw bench and carriage structure is shown in more detail in Figs.13 to 16. The carriage is provided with wear plates, for example,formica, but preferably more durable material, such as bronze, where thegreatest wear friction occurs. Since the draw mechanism, in theconstruction shown, extends laterally from the carriage, the drawingstress is lateral of the carriage and therefore imposes a lateral strainor torque upon the carriage and causes the greatest wear at two opposingside terminal portions. At these portions, therefore, the wear platesshould be metal while formica will sufiice for'the other bearing or wearstrips.

.As shown in Figs. 13 through 14a, the carriage 92 has relatively longbronze wear strips 94 and 95 on opposite side ends and short formicastrips 96 and 97 on the other opposite side terminals. It is evidentthat the drawing stress will cause a clockwise twisting force on thecarrilage and produce the greatest friction on the bronze p ates.

Also the carriage has full length top and bottom formica wear strips oneach face. The two top strips are numbered 98 and 99 and the bottomstrips are numbered 100 and 101. The top strips 98 and 99 are relatively narrow, their inner edges terminating with the overhang 89a, andthe bottom strips 100 and 101 are of a width to reach to the channel inthe bottom of the draw bench.

The top and bottom face wear strips are provided with lubricatingchannels or grooves, and lubricating oil is pumped into these from thegear box as will be described.

The forward wall of the gear box has in its upper portion two verticaloil passages 102 and 103 which are spaced to register with passages 102aand 103a, respectively, in the draw bench extending through to the slidespace. The pump 83 delivers oil from tank to the bearings in the box andto the passages 102 and 103. Conduit has a branch 85a which delivers oilto the bearing 76 and to the other bearings for shaft 73, and it alsodelivers to the bearings for the shafts of pinion 87 and bull gear 88.Thence, it continues on and has branch outlets connected with thepassages 102 and'103.

The formica strips 100 and 101 on the bottom of the carriage have fulllength oil grooves 100a and 101a together with several ,Iateral groovesand the top formica strips have interrupted oil .gr ooves .98a and 99a.

The passages 102a and 103a lead to the full length grooves 100a .and101a on the under side ot wear strips '100 and 101, and branching fromeach of passages 102a and 103a is a-passage 194 leading up,;throughtherespective side wall ,of the .drawbench andinward and downwardthrough the overhead portion 89a into the top grooves 98a and 99a.Vertic alpassages and 10% lead up from the respective grooves 100a and101a into the carriage slide 92 and'branch laterally into recesses 105in wear plates 94, 95, 96 and97 by way of lateral passages 106. Thereare .four passages102b and .1031; for the bronze wearplates v9.5 and.94,.respectively, and two passages 1021) and .1031) for theformica-wearplates 96 and 97, respectively. It will .be seen that thelength of eachsection of the interrupted grooves98g and 99a is such that the grooveisentirely ,coveredby .the overhang 89a when oil is delivered to it by thepassage v104.

The excess lubricating oil delivered to the carriage through thepassages abovedescribed runs-down into the channel for the rack andcollects in a space around a rectangular angle member .107 surroundingthe aperture for the bull gear in the bottom of the draw bench, and fromthence it runs through a hole shown in Fig. 7 into a gutter 108 and isled to a tube 109 anddelivered into the oil sump in the bottom of thegear case. The oil level .ismaintained in the gear case about at the topof brace 79 and of the tank 80, so that thegear 86 and bull gear 88 runin it, as shown in Fig. 8.

The'length of the carriage and rack is adjusted to the maximum length ofsheets to be drawn-and the draw bench is provided with bumpers 110 (seeFig. 1361) at its ends to limit the movement of the carriage in case theautomatic means for stopping the motor fails, the length of the rackbeing such that the teeth leave the bull gear just before the bumpersare engaged.

It is desirable on occasions to extend the draw bench and carriage toformunusually long sheets, for example. One of the advantages of thedraw bench construction above described is that it may readily beextended.

Figs. 11 and 12 illustrate means forsuch extension. The draw bench 89has secured underneathit ,on each side of the rack channel aplate 111 bymeans of screws 112 and these plates have extensionsto connect to thedraw bench extension 89Ex. The plate extensions have elongated screwholes through which pass screws 112a and screw into the bottom of thedraw bench extension 89Ex. Extending from the end of each plate 111 is athreaded tie rod 113 which extends through a leg 99 or other downwardlug on the draw bench extension and has a nut and washer on its threadedend which, when tightened up, .bears against the leg and draws the twosections of the draw bench together. A gasket 114 will be provided atthe point, as shown, to prevent. leakage of lubricating oil.

A way is also shown to join an extension 92Ex to the carriage 92. Asshown two screws protrude from the ends of each section disposed so asto aline, and those in one section have right hand threads and those inthe other section have left hand threads. A nut on each pair completesturnbuckles 115. Thus, the two sections are drawn together and a key 116is provided at the joint to aline and support the two edges vertically.

It will be understood that for a given extension'of .the carriage andrack the draw bench must have an equal extension on eachend.

Fig. 12 shows a super structure carried .by thecarriage which is notrelated to thepresent invention. As shown this super structure'isattached tothecarriage by a support 117. Fig. 12 illustrates how thissuper structure may be extended to compensatefor an extension of thecarriage.

As stated above, the sheet pulling or drawing mechanism is carried andtranslated 'by the carriage. 'In'the illustrated construction, thisconsists of a laterally .extending arm 118, and a draw head 119 carriedby the arm. The headfhas 'jawsfor gripping the'leadingedge of the sheetbeing drawn. vA'leg 12 0 supports the outer end of theiarm.

It is obvious that the particular construction of the draw bench andassociated mechanism as shown in the drawings and above particularlydescribed may be modified within the scope of the invention as definedin the following claims.

What is claimed is:

1. Draw'bench mechanism for sheet forming machines operating on theforming-by-drawing principle comprising a base, a pair of uprightssecured'to the base, transversely disposed elongated forming elementssupported within and spanning .the uprights in position to have a sheetdrawn over them in succession, a gear box supporteduponthe base, .anelongated channel draw bench member supported upon and secured to the'gear box at a point intermediate its ends, a carriage slidable in thedraw bench, a rack on the under side of the carriage, a gear in the gearbox operatively engaging the rack, an inward extension on each side ofthe draw bench constituting an overhang, bearing upon and guiding therespective ,top edges of the carriage, oil passages in the draw benchleading to the under faces of said overhangs, means for deliveringlubricating oil under pressure to-said, passages and a draw headattached to and movable with the .carriage and adapted to engage anddraw .a sheet ,oversaid forming elements.

2. Draw bench mechanism for sheet forming machines as defined in claim 1in which theoverhangs extend from the forward end of the bench to apoint .on the .gear box at the rear of the engagement of said gear and,are discontinued rearwardly of said point.

3. Draw bench mechanism for sheet forming machines as defined in claim 2in which the carriage has full length wear strips on each of its top andbottom edges and the top wear strips have each a discontinuouslongitudinaloil groove on its exposed face having longitudinal sectionsadapted to register successively with the respective oil deliverypassage leading to the under face of the overhang, the oil deliverypassages being disposedrelative to the length of the oil groove sections.to interrupt delivery of oil to the sections successively before theyemerge from under the respective overhangs inthe'return movement of thecarriage.

4. Draw bench mechanism for sheet'forming machines as defined in claim 3in which the bottom'wear strips have each a continuous longitudinal oilgroove on its exposed face, together with an oil passage in the drawbench leading to each oil groove in the bottom .wear strips, togetherwith means for delivering lubricating oil under pressure to said lastnamed passages.

5. Draw bench mechanism for sheet forming machines as defined in claim 4in which the oil passages in the draw bench leading to the under facesof the overhangs branch from the oil passages leadingto the oil groovesin the bottom wear strips.

6. Draw bench mechanism for sheet forming machines as defined in claim 5together with an oil .pump .in the gear box, power means for the oilpump, and aconduit connecting the pump with each of the oilpassagesinthe draw bench leading to the oil grooves in the bottom .wear strips.

7. Draw .benchrnechanism'for sheet forming, machines 'as defined inclaim 6 together with lateral Wear strips on the side edges of thecarriage, and oil passages inz th e carriage leading from the continuousoil-grooves in the bottom wear strips on the bottom faceof the carriageto the external faces of the lateral wear strips .on therespective sideedges of the carriage.

References Cited in the file of this patent UNITED STATES PATENTS McGillMay 25, 1909 Moltrup June 30, 1931 Henderson Aug. 8, 1933 De SaussureOct. 17, 1933 Dempsey June 6, 1939 Hou Dec. 12, 1939 Baker Aug. 10, 194310 Picton July 26, 1949 Anderson Sept. 6, 1949 Daugherty July 22, 1952White Apr. 6, 1954 Daugherty Apr. 13, 1954 Ratzlafl May 18, 1954 HalldenOct. 23, 1956 FOREIGN PATENTS Great Britain Jan. 20, 1954

